W312-02 Datasheet, PDF (13/21 Pages) Cypress Semiconductor – FTG for VIA K7 Series Chipset with Programmable Output Frequency

W312-02
Table 4. Additional Frequency Selections through Serial Data Interface Data Bytes
Input Conditions
Output Frequency
FS4
FS3
FS2
FS1
FS0
SEL4 SEL3 SEL2 SEL1 SEL0
CPU
3V66
0
0
0
0
0
156.0
78.0
0
0
0
0
1
154.0
77.0
0
0
0
1
0
152.0
76.0
0
0
0
1
1
147.0
73.5
0
0
1
0
0
144.0
72.0
0
0
1
0
1
142.0
71.0
0
0
1
1
0
138.0
69.0
0
0
1
1
1
136.0
68.0
0
1
0
0
0
124.0
62.0
0
1
0
0
1
122.0
61.0
0
1
0
1
0
117.0
78.0
0
1
0
1
1
115.0
76.7
0
1
1
0
0
113.0
75.3
0
1
1
0
1
108.0
72.0
0
1
1
1
0
105.0
70.0
0
1
1
1
1
102.0
68.0
1
0
0
0
0
Reserved
Reserved
1
0
0
0
1
Reserved
Reserved
1
0
0
1
0
Reserved
Reserved
1
0
0
1
1
200.0
66.6
1
0
1
0
0
190.0
76.0
1
0
1
0
1
180.0
72.0
1
0
1
1
0
170.0
68.0
1
0
1
1
1
150.0
75.0
1
1
0
0
0
140.0
70.0
1
1
0
0
1
120.0
60.0
1
1
0
1
0
110.0
73.3
1
1
0
1
1
66.6
66.6
1
1
1
0
0
200.0
66.6
1
1
1
0
1
166.6
66.6
1
1
1
1
0
100.0
66.6
1
1
1
1
1
133.3
66.6
PCI
39.0
38.5
38.0
36.8
36.0
35.5
34.5
34.0
31.0
30.5
39.0
38.3
37.7
36.0
35.0
34.0
Reserved
Reserved
Reserved
33.3
38.0
36.0
34.0
37.5
35.0
30.0
33.3
33.3
33.3
33.3
33.3
33.3
PLL Gear
Constants
(G)
48.00741
48.00741
48.00741
48.00741
48.00741
48.00741
48.00741
48.00741
48.00741
48.00741
48.00741
48.00741
48.00741
48.00741
48.00741
48.00741
Reserved
Reserved
Reserved
48.00741
48.00741
48.00741
48.00741
48.00741
48.00741
48.00741
48.00741
48.00741
48.00741
48.00741
48.00741
48.00741
Programmable Output Frequency, Watchdog Timer and
Recovery Output Frequency Functional Description
The Programmable Output Frequency feature allows users to
generate any CPU output frequency from the range of 50 MHz
to 248 MHz. Cypress offers the most dynamic and the simplest
programming interface for system developers to utilize this
feature in their platforms.
The Watchdog Timer and Recovery Output Frequency fea-
tures allow users to implement a recovery mechanism when
the system hangs or getting unstable. System BIOS or other
control software can enable the Watchdog timer before they
attempt to make a frequency change. If the system hangs and
a Watchdog timer time-out occurs, a system reset will be gen-
erated and a recovery frequency will be activated.
All of the related registers are summarized inTable 6.
Document #: 38-07259 Rev. *B
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